Great piece from @RunCompetitor about why power might be the ultimate training metric for runners.

Since the 1950s, distance runners have trained by following structured programs and workouts backed by physiological testing and years and years of positive results. Beginning in the late 1980s, heart-rate monitors added a new dimension to training, allowing for the advent of workouts based on specific heart-rate zones. Both methods have helped runners and triathletes of all levels improve their performance. By the early 2000s, GPS-enabled smartwatches made it easy to monitor pace, distance, elevation and other types of data. As the modern age of wearable tech has started to unfold, a new measurement technology has the ability to revolutionize training for runners: the power meter. Cyclists have used power meters since the 1990s to accurately measure how much power they’re outputting and how that effort corresponds with their physiology. Power is the primary metric for cyc...